The Mental Tenacity of Larry Bird

"Riley poured over tapes of Bird, pointing out specific tendencies to his team, such as Bird's preference to bring the ball up left-handed and his ability to split the double teams by positioning his feet in between the trap. Yet, all the technical tips, Riley knew, would not offset the true strength of Bird's game: his mental tenacity. 'You had to deal with his psyche before you could even discuss the basketball aspect of it,' Riley explained. 'I always told my guys, you will never be able to beat Bird until you understand how much he wants to win and what he'll do to make sure he wins. We had to be above and beyond him mentally, and I wasn't always sure it was possible." 
Larry Bird and Earvin Magic Johnson
When The Game Was Ours 


How mentally determined are you? 
Have you measured your mental stamina?
How are you developing your mental endurance?